Everything on the blower was factory including the upper pulley (no porting etc.). Also, the blower has never been touched apart from changing the belt when doing the lower pulley upgrade. I heard of this happening to someone else so it may have been a weak unit from the factory. Before I took it apart I kept getting that howling sound described in another thread. That individual took his to the dealer and had it replaced under warranty. So if you get this howling sound.......better keep an eye out because it was more than a bad bearing for me.